Typical railway cars usually include at least two railway trucks at either end thereof. The railway truck consist of a rigid frame having a pair of axles rotatably connected thereto and supported by wheels. The railway trucks are pivotally connected to the rail car supported thereby to accommodate turns in the railway; however, derailments sometimes occur in a turn when the spacing between the rails is not consistent and the rigid nature of the railway truck frame forces one or more of the wheels from a supporting rail.
A more specialized use of railway trucks is even more likely to facilitate the derailment situation discussed above. As is shown in U.S. Pat. No. 3,877,390 issued to Wallace, the inventor herein; independent railway trucks are used to transport a highway vehicle, such as a mobile crane, over a railway. Such highway vehicles are not designed for railway travel and are particularly bulky and top-heavy when supported by the relatively small railway trucks shown in Wallace '390. Note also that the frame of a typical railway car is designed to provide stability between the two supporting railway trucks whereas the railway trucks shown in Wallace '390 act relatively independently having only a loose connection with the highway vehicle carried thereby. Further, the railway trucks in Wallace '390 are self-driven which magnifies the independence between the two cars. The aforesaid combination disclosed in Wallace '390, of a top heavy load transported by rigid, independently driven railway trucks, may be susceptible to derailment when negotiating curves or inconsistencies in the railway. What is needed and not known by the inventor to exist in the industry is a self-driven railway truck having a flexible frame and flexible drive assembly connected thereto and in operative connection with the axles and wheels that will accommodate flexion of the frame at various points thereon to safely negotiate curves and inconsistencies in the railway.